1. Field of the Invention
The present invention relates to a deflector and in particular to a deflector in which an electromagnetic force is used.
2. Description of the Related Art
A structure disclosed in Japanese Patent Application Laid-open Publication No. Hei 7-218857 for example, is hitherto known for detecting a displacement angle of a mirror of a deflector. FIG. 14 denotes a structure disclosed in Japanese Patent Application Laid-open Publication No. Hei 7-218857. In this structure, a capacitance type displacement-angle detection method is used. Electrodes 16A and 17A are provided on a rear surface of a mirror 12 at positions symmetrical with respect to an axis 11. Electrodes 16B and 17B which form pairs with the electrodes 16A and 17A are provided on a side of a glass substrate 14. Thus, condensers C1 and C2 are formed. A displacement angle of the mirror 12 is detected based on a difference in capacitance of the two condensers C1 and C2 due to an angular displacement of the mirror 12.
However, in the structure disclosed in Japanese Patent Application Laid-open Publication No. Hei 7-218857, the electrodes 16A and 17A on one side of the electrostatic capacitance which detect an angle of the mirror 12, are on the mirror 12 which is a movable plate. Accordingly, for detecting the electrostatic capacitance, it is necessary to draw wires connected to the electrodes 16A and 17A outside a deflector via a torsion bar which supports the movable plate. For this, it is necessary to form a wiring on the torsion bar. As a result of this, a degree of freedom of designing the deflector is declined.